Dr. Christian Papp studied Chemistry at the
Friedrich-Alexander-Universität Erlangen-Nürnberg. He finished his PhD in the
group of Prof. Hans-Peter Steinrück with summa
cum laude in 2007; the title of the thesis was: “Model systems in
heterogeneous catalysis”. Thereafter, he moved with a prestigious Feodor Lynen
stipend of the Alexander von Humboldt foundation to work at Lawrence Berkeley
National Laboratory and University of California, Davis with Prof. Charles S.
Fadley. During his postdoctoral visit he conducted pioneering experiments on
soft x-ray standing wave experiments and hard x-ray photoelectron spectroscopy
of strongly correlated materials and spintronic systems. In 2009, he returned
to Germany to become group leader of the “Surface and in situ spectroscopy
group” at the Lehrstuhl für Physikalische Chemie II in Erlangen. His work
focuses on in situ experiments primarily conducted with synchrotron radiation
at BESSY II in Berlin.
F. Späth, C. Papp et al. 2D Materials 4 (2017) 35026His research is focused on the in situ analysis of surfaces and interfaces facilitating synchrotron radiation for 1) the fundamental understanding of surface processes, 2) materials characterization and synthesis, 3) the analysis of heterogeneous catalysis, 4) the development of new in situ techniques. In the following his main achievements and projects of the past years are summarized. Fundamental insights in surface reactions
R. Streber, C. Papp et al. Angew. Chem. Int. Ed. 48 (2009) 9925.
Liquid organic hydrogen carriers Besides the fundamental understanding of the reaction of small molecules, the reactivity of larger molecules is investigated in the framework of the Cluster of Excellence ‘Engineering of Advanced Materials’ and a cooperation with BMW. Studying these particular systems is motivated by one of the grand present challenges of mankind, namely the storage of energy. Among several approaches, one potential solution is “chemical storage” of hydrogen using Liquid Organic Hydrogen Carrier (LOHC) materials. These substances are high boiling organic molecules, which can be reversibly hydrogenated and dehydrogenated using heterogeneous catalysts.Despite the high relevance of such systems, the molecular level understanding of the catalytic dehydrogenation and hydrogenation of LOHCs is still at its infancy. This is partly due to the size of the molecules (forty and more atoms) which makes them a major challenge for surface science methods. Nevertheless, the Papp group demonstrated that by an in situ XPS study of such molecules on model catalysts, one can obtain detailed insights into the mechanisms of dehydrogenation and also of relevant side-reactions, at the molecular level. See e.g. C. Gleichweit C. Papp et al. ChemSusChem 6 (2013) 974.
Growth and Chemical Modification of Graphene
J. Englert, C. Papp
et al. Nat. Chem. 3 (2011) 279.
Near ambient pressure X-ray photoemission A further in situ technique used in the group of C. Papp is near ambient pressure X-ray photoelectron spectroscopy (APXPS), a modern tool to study the surface of liquids and solid surfaces under ambient conditions. This technique allows insights in various areas, particularly in atmospheric, environment and catalysis sciences. NAPXPS adds important new information in the field of surfaces in the presence of gases and vapors, closing the gap between high pressure and ultra high vacuum conditions. The systems studied range from model catalysis systems such as the CO oxidation on platinum, to of novel heterogeneous catalysts as Pt nanoparticles on and in titania nanotubes, ethanol steam reforming on Co ceria systems, bimetallic catalysts such as Pt/Ga and to liquid systems as in the case of the CO2 capture reaction of functionalized ionic liquids. See e.g.I. Niedermayer, C. Papp et al. J. Am. Chem. Soc. 136 (2014) 436.
Hard X-ray photoemission and angle resolved hard X-ray photoemission The use of hard X-rays in photoemission opens the new opportunities in the field of materials characterization. The inherent surface sensitivity of soft X-rays paved the way to investigate surface properties of novel materials; nevertheless, information on the bulk properties such as the electronic structure cannot be obtained easily. C Papp was involved in the pioneering experiments that showed that hard x-rays with a significantly higher escape depth of the photoelectrons allow to directly study buried interfaces, omnipresent in electronic devices, as e. g, gating materials, or the bulk electronic structure, with this new approach. See e.g.A. Gray, C. Papp et al. Nat. Mat. 10 (2011) 759. Soft X-ray standing waves S. H. Yang, C. Papp et al. Phys. Rev. B 84 (2011) 184410.
|